In: Math
1. An exponential relationship can be defined by the formula f(x)=30(0.42)^x where y=f(x). Complete each of the following exercises.
As x increases, y answer:decreases
What is the function's initial value (the value of y when x=0)?
f(0)=
What is the function's 1-unit growth or decay factor?
What is the function's 1-unit percent change?
What is the value of f(3.25)?
2. The exponential function f(t)=18.6(0.964)^t where w=f(t) models the water level (in meters) in a certain reservoir in terms of the number of weeks since June 1.
As t increases, w answer:decreases
What was the water level in the reservoir on June 1?
What is the function's 1-week growth or decay factor?
What is the function's 1-week percent change?
What was the water level in the reservoir 5.5 weeks after June 1
3.
In a certain exponential relationship, whenever x changes by 1, y changes by -4%. For this relationship, the 1-unit growth (decay) factor is
In a different exponential relationship, whenever x changes by 1, y changes by -22%. For this relationship, the 1-unit growth (decay) factor is
In a third exponential relationship, whenever x changes by 1, y changes by -57%. For this relationship, the 1-unit growth (decay) factor is
1.
a. In this case, the base is 0.42 < 1, this implies as x increases y decreases
b. When x = 0
=> f(0) = 30
c. 1-unit decay factor = 0.42
d. 1-unit percent change
= (1 - 0.42) * 100%
= 0.58 * 100 %
= 58 %
e. when x = 3.25
=> f(3.25) = 1.789293
2.
a. In this case, the base is 0.964 < 1, this implies as x increases y decreases
b. When x = 0
=> f(0) = 18.6
Therefore, the water level in the reservoir on June 1 = 18.6 m
c. 1-week decay factor = 0.964
d. 1-week percent change
= (1 - 0.964) * 100%
= 0.036 * 100 %
= 3.6 %
e. when t = 5.5
=> f(5.5) = 15.20326
Therefore, the water level in the reservoir 5.5 weeks after June 1 = 15.20326 m
3. a) r = - 4 % = - 0.04
Therefore,
1-unit decay factor
= 1 - 0.04
= 0.96
b) r = - 22 % = - 0.22
Therefore,
1-unit decay factor
= 1 - 0.22
= 0.78
c) r = - 57 % = - 0.57
Therefore,
1-unit decay factor
= 1 - 0.57
= 0.43